July sees the annual highlight of the cycling road-race calendar - the Tour de France.
It is one of the hardest endurance events in world sport and offers a chance to follow the team tactics of road racing, while marvelling at the riders' athleticism and will power. In 20 separate day long stage races 22 teams of nine riders will cover 2,283 miles, and in the process traverse some of the highest mountains in France.
Yet as well as being astonished at what the riders will achieve, it is also necessary to recognise that they will be driven to the very limits of human endurance by their managers and the organisers. Both are keen to create the kind of spectacle that will encourage interest from TV and investment from sponsors. This means putting pressure on the riders to improve their performance and drive themselves up to, and beyond, their limit.
The average speed of the whole race is on an upward curve. The riders will cover the tour at an average speed of 38 to 39 km per hour. This compares to 33 km per hour in 1947 and 35 km per hour in 1975. Each year the organisers put in more mountains for the riders to climb and more mountain top finishes, because this immense hardship is what attracts the sponsors.
There is an obvious conflict between sporting excellence and commercial interests which has been central to the tour since its inception.
The Tour de France was born out of a circulation war between two French cycling magazines at the start of the 20th century. The first Grande Boucle took place in 1903 with participants expected to ride 2,428 km between 1 July and 19 July. The distances covered immediately generated interest in the event but also led to criticism that the sponsors were exploiting working class athletes for their own gain. Analogies were drawn between the dehumanising, overly regulated life of the tour cyclist and that of the modern factory worker.
In 1924 the defending champion, Henri Pelissier, quit the tour in protest at the distance of the race and the petty rules riders were meant to adhere to. Campaigning journalist Albert Londres took up the case, recounting the effects the race had on the cyclists - the illnesses, the weight loss and the drugs they used to put up with the pain.
He described the race as a "tour of suffering" and the cyclists as the "forçat de la route" (the convict, or chain gang labourers, of the road). Pelissier wrote to the Communist Party paper L'Humanité saying that he accepted the "excessive fatigue, suffering, pain" of his profession but he and his fellow racers wanted to be "treated as men, not dogs".
L'Humanité kept up the pressure during the inter-war years, denouncing the criminal exploitation of the "pedal workers" by the "sports profiteers". They linked their attack to a general critique of overwork, speed-ups and exploitation by French capitalism on all workers.
The remarkable thing about this is how little has changed. Today the tour pulls in phenomenal sums of money - it is worth more than the total income of all the other European races put together. London mayor Ken Livingstone had to pay £3 million to entice the tour to start in London in 2007.
Yet only a tiny proportion of this will go to the 400 or so professional cyclists on the European circuit. The lowest paid earn as little as £20,000 a year; most earn between £40,000 and £65,000. It is only the top team leaders who can command contracts worth hundreds of thousands of pounds.
Seasons are relatively long (about six months of hard racing) but careers are short and injury is common. On average there are five injuries a week during the season, which means each rider has a one in four chance of injury. In fact, the injury rate is so high that most firms will not provide health cover for tour cyclists.
And the injuries are usually serious. Riders travel at high speed, with little protection. When they crash, their bodies hurtle into metal machines and onto road surfaces. Flesh is ripped and burned, and bones are broken - yet riders are under intense pressure to get back on the bike and continue on.
The pain, suffering and demands placed on participants have one other notable outcome. Professional cycling is, and always has been, racked by drug use. The teams demand quick recoveries and improved performances. Failure means contracts will not be renewed.
Therefore, the teams encourage riders to do what is necessary - and this means using all types of performance enhancers. When individuals are caught they are abandoned as "cheats". Yet there is no doubt they are the victims of a callous system of exploiting the modern day "forçat de la route".